diff --git a/DESCRIPTION b/DESCRIPTION
index 5c10ce47..904a59c8 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Type: Package
 Package: effectsize
 Title: Indices of Effect Size
-Version: 0.8.6.2
+Version: 0.8.6.3
 Authors@R: 
     c(person(given = "Mattan S.",
              family = "Ben-Shachar",
diff --git a/NEWS.md b/NEWS.md
index 05d6febf..bfd8f3f0 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -6,6 +6,10 @@
 
 - `repeated_measures_d()` to compute standardized mean differences (SMD) for repeated measures data.
   - Also supported in `effectsize(<t.test(paired = TRUE)>)`
+  
+## Bug fixes
+
+- `nnt()` now properly accepts the `y` argument.
 
 # effectsize 0.8.7
 
diff --git a/R/xtab_diff.R b/R/xtab_diff.R
index a80f6455..2346f85d 100644
--- a/R/xtab_diff.R
+++ b/R/xtab_diff.R
@@ -304,7 +304,7 @@ nnt <- function(x, y = NULL, ci = 0.95, alternative = "two.sided", ...) {
     return(effectsize(x, type = "nnt", ci = ci, ...))
   }
 
-  out <- arr(x, y = t, ci = ci, alternative = alternative2, ...)
+  out <- arr(x, y = y, ci = ci, alternative = alternative2, ...)
   out[[1]] <- 1 / out[[1]]
   colnames(out)[1] <- "NNT"
 
diff --git a/tests/testthat/test-xtab.R b/tests/testthat/test-xtab.R
index aaa9bbb6..667127cb 100644
--- a/tests/testthat/test-xtab.R
+++ b/tests/testthat/test-xtab.R
@@ -200,6 +200,14 @@ test_that("oddsratio & riskratio", {
   expect_equal(ARR[[1]], -0.4891775, tolerance = 0.001)
   expect_equal(ARR$CI_low, -0.8092576, tolerance = 0.001)
   expect_equal(ARR$CI_high, -0.1690974, tolerance = 0.001)
+
+  # fix
+  set.seed(111)
+  x <- rbinom(10, 1, 0.5)
+  y <- rbinom(10, 1, 0.5)
+
+  expect_no_error(NNT <- nnt(x, y))
+  expect_equal(NNT[[1]], arr_to_nnt(arr(x, y)[[1]]))
 })